How do you return to the default view (the one you see when blender starts)?
I assume you are wanting to have the same arrangement of windows as when you start blender.
If you have chosen another screen layout at the top: , just choose the Default layout.
If you have modified the Default layout, you can reset all your layouts to normal by:

Save your current file.
Choose File &gt; New and reload the startup file.
Open your file, but make sure that the &quot;Load UI&quot; checkbox isn't checked: 

To save your new layouts, save your file, and the new (default) layout will be saved with it.

If you just want to reset the view of the 3D view in the screen layout &quot;Default&quot;, there's some python code that will make that happen.  So temporarily change one of your windows to the type &quot;Python Console&quot; and paste this code in:
for space in [area.spaces[0] for area in bpy.data.screens['Default'].areas if area.type == 'VIEW_3D']:
    space.region_3d.view_matrix = Matrix((
        (0.4100285768508911, 0.9119762182235718, -0.013264806941151619, 0.0),
        (-0.401742547750473, 0.19364379346370697, 0.8950446844100952, 0.0),
        (0.8188281059265137, -0.36166486144065857, 0.44577914476394653, -14.988801002502441),
        (0.0, 0.0, 0.0, 1.0)))

This will reset the view for any 3D view windows you have.
Note:
The numbers in the matrix above are not something I figured out using complex math.  I just opened a new blender file and read the value in
bpy.data.screens['Default'].areas[-1].spaces[0].region_3d.view_matrix